CLINICAL Why (and when) I love Biodentine Specialist Endodontist Peter Raftery explains how Biodentine can be the ideal material for root canal procedures. The appearance of narrow canals and curvy roots on a pre-op periapical radiograph rightly alerts us to the prospect of a tricky root canal treatment.¹ Yet I would argue that the technical challenge posed by cases at the other end of the spectrum – those teeth with wide, straight canals – shouldn’t be underestimated. At first glimpse, these ought to be simple cases since they are normally anterior teeth and there is usually little difficulty in negotiating the canals to full length, but controlling for length during both the cleaning and filling stages can be especially difficult. Cleaning It is possible to clean the full canal system only once the canal length is determined. Electronic length determination (apex locator accuracy) is best when the canal is relatively dry and when there is snug contact between the file tip and the apical canal walls. With a wide canal this snugness of fit is lost, which is why apex locators working length determination are less reliable in cases where the apical foramen is enlarged.² Since the 1980s we have known that, on its own (ie without an antibacterial irrigant), mechanical debridement of infected canal walls was insufficient to render them bacteria free.³ Micro-CT scans of extracted teeth show that a significant proportion of canal surfaces remain uninstrumented following preparation, with the shortcoming most pronounced in wide canals where up to 50% of the canal remains untouched.4 Pre-op Filling Teeth with wide canals and straight roots lack the usual friction, taper and apical constriction normally afforded by the canal walls so that there is little to stop the extrusion of root-filling material through the apex during vertically compacted obturation. This is considered a challenge since not only are overfilled teeth associated with the lowest endodontic success rates5 but various sensitive anatomical structures are in harm’s way when endodontic procedures are not confined within the root canals.6 Post-op Case study Peter Raftery Specialist endodontist based in Portsmouth, having trained in endodontics at the Eastman Dental Hospital, London. Peter is a member of the Royal College of Surgeons in England (MRD) as well as Edinburgh (MEndo). 12 Denplan INSIGHT Magazine May 2014 The following case nicely shows a successful outcome in a case of wide canals and straight roots. The patient, a 20-year-old female, was referred by her dentist for endodontic management of her LR7 which had been associated with a draining buccal sinus for the preceding month. Clinical examination revealed that the LR7 had a large distal Class II amalgam restoration. A draining Six month review sinus was noted bucally to the tooth which was Grade II mobile but not associated with significantly increased periodontal probing defects. We reached and discussed a diagnosis of chronic apical periodontitis with suppuration LR7. In light of her overall sound periodontal state I felt that the mobility and periodontal destruction (as well as the periapical lesion) would resolve with successful management of the endodontic infection. On removal of the defective restoration, the seal and appearance was improved with a Fuji IX glass ionomer cement restoration. Following rubber dam isolation, endodontic access yielded three canal orifices. The walls of the wide, straight canals were debrided lightly with metal files. Plenty of time was then dedicated to thorough irrigation of the canals with plentiful 5% concentration sodium hypochlorite. At the six month review the patient had no complaints. The sinus had resolved and the mobility had returned to that of her normal adjacent teeth. A periapical radiograph confirmed resolution of the radiolucency both apically and periodontally. The merits of a cast restoration were reiterated. Conclusions Biodentine was the ideal material for canal obturation, in this case from time saving and biological perspectives. In my hands there weren’t enough hours in the day or accessory gp points in the practice to have completed cold lateral condensation. I was concerned that any attempt at a warm vertical obturation would have resulted in significant extrusion – possibly compromising the nearby ID nerve. The interface between the root filling material and the periapical tissues is normally small, but when the apical foramen is considerably widened (as was the case here) a more biocompatible filling material is desirable. The biocompatibility of Biodentine is second to none and the improved handling characteristics (12 minute setting time) made it the ideal choice. CLINICAL A sinus tracer radiograph tracked the source of the discharge to the root ends of LR7. The canals appeared wide and the roots were straight. Although radiolucency was evident periapically, it was not confined to a discreet apical lesion; radiolucent bands were seen extending up the mesial and distal root surfaces. The restoration – which extended into the pulp chamber – had a marginal discrepancy, possibly secondary caries. Although Biodentine served as the ideal root filling material in this case, its use in so many other applications makes it an essential part of the dentist’s armamentarium. It is ideally suited for use as a temporary enamel restoration, permanent dentine restoration in deep or large carious lesions, a material for pulp capping or pulpotomy. It is suitable for repairing root and furcation perforations, sealing internal/external resorptions, for apexification and for retrograde root-end fillings. References ¹ www.rcseng.ac.uk/fds/publications-clinical- guidelines/ clinical_guidelines/documents/complexityassessment.pdf ² Stein TJ, Corcoran JF, Zillich RM (1990) Influence of the major and minor foramen diameters on apical electronic probe measurements. Journal of Endodontics 16, 520–2. ³ Byström A & Sundqvist G (1981). Bacteriologic evaluation of the efficacy of mechanical root canal instrumentation in endodontic therapy. Scand J Dent Res. 1981 Aug;89(4): 321–8. Hübscher Barbakow & Peters (2004) Root canal preparation with Flexmaster: canal shapes analysed by micro-computed tomography. International Endodontic Journal 36, 740–7. 4 Ng Y-L, Mann V, Rahbaran S, Lewsey J, Gulabivala K. 2008. Outcome of primary root canal treatment: systematic review of the literature – Part 2. Influence of clinical factors. International Endodontic Journal, 41, 6–31. 5 Knowles KI, Jergenson MA, Howard JH (2003). Paresthesia associated with endodontic treatment of mandibular premolars. Journal of Endodontics, 29(11):768–70. 6 Conventional electronic length determination was likely to be difficult because of the canal size so an estimate was made from the pre-operative radiograph. From this estimate, the true canal length was confirmed via the ‘paper-point technique’ whereby a large paper point is briefly inserted into a canal before removal and inspection of the tip. The working length is reflected in the distance from the coronal reference point to the location of the wet-dry junction on the paper point. After disinfection, Biodentine was mixed according to the manufacturer’s instructions. Small increments were placed into the pulp chamber with a flat plastic and then tamped down to full working length using a measured, large paper point. Once Biodentine filled the canal to orifice level, I packed a further increment of Fuji IX into the access cavity. www.denplan.co.uk 01962 828000 13